This invention relates to a radar system primarily for aircraft, using automatic horizontal and vertical scanning, capable of displaying of radar signals superimposed with terrain elevation data in a plan view and in supplemental front and side vertical views.
Each year aircraft crash in unacceptable numbers. Investigations into these crashes show that often the cause of the crash is not due to mechanical problems. These types of crashes are described as controlled flights into terrain. Controlled flights into terrain often result from a pilot's lack of three dimensional situation awareness. A graphic display of the aircraft position relative to terrain would improve such awareness. Pilots need information about their aircraft's position relative to terrain elevation in an easy to read and comprehend presentation. The availability of detailed, world-wide data bases providing terrain elevations make such a display possible.
Most large aircraft have Ground Proximity Warning Systems (GPWS) but the GPWS only provides a warning alarm rather than a visual display. This present invention provides a simple, accurate way of displaying to the pilot a visual image of the aircraft position relative to terrain elevation as well as to weather conditions in a form that may be seen at a glance with little pilot input. A glance at the display would help the pilot distinguish a GPWS's true warning signal from a false signal.
Conventional terrain alert warning systems, such as GPWS, presume either an aircraft descending into terrain or flying into rising terrain and provide "pull-up" alerts. However, some accidents occur in steep mountains where escape by pull-up is not a realistic possibility because the terrain rises higher than the aircraft can climb. In such terrain, pilots need a visual display, including a vertical presentation of the terrain, with a terrain warning to supplement the pull-up alert.